From Guild Wars 2 Wiki
Disgruntled Ooze is a trophy required for the The Juggernaut III: The Colossus legendary weapon collection.“
Hint: Feed Grumble Cakes to your Tiny Chromatic Ooze. This delightful cake can sometimes be found in the Dragon Chest after defeating the Shatterer.
— In-game description
- This item does not enter your inventory. It is added directly to the collection.